US: What’s behind the dramatic rise in 3-generation households?

In a recent study, I discovered that the number of kids living with their parents and grandparents – in what demographers call a three-generation household – has nearly doubled over the past two decades.

Why has this been happening? And is it a good thing or a bad thing?

The answers are complex. The reasons for the trend are as broad as social forces – like a decline in marriage rates – to unique family circumstances, like the loss of a parent’s job.

The trend is worth studying because by better understanding who children live with, we can design better policies aimed at helping kids. Programs targeting kids usually overlook these other people living under the same roof. But odds are that if grandma’s there, she matters, too.

The flexible family unit

A three-generation household is just one type of a living arrangement that falls under the umbrella of what demographers call a “shared household” or a “doubled-up household.”

In a shared household, a child lives with at least one adult who isn’t a sibling, parent or parent’s partner. It could include a cousin, aunt, uncle, grandparent or family friend.

In 2010, about 1 in 5 children were living in a shared household, a 3 percentage-point increase from 2007. In a 2014 study, I tracked the same kids over time and found that by age 10, nearly half of children in large U.S. cities had lived in a shared household at some point in their lives.

Then, to probe further, my colleague and I used two large census data sets to study trends by the type of shared living arrangements.

We found that, overall, the percentage of children in shared households had increased since 1996.

But the rise was nearly entirely driven by an increase in just one type of household: three-generation households – sometimes referred to as multigenerational households – in which children live with at least one grandparent and one or both parents.

We also found that the share of children living in three-generation households has risen from 5.7 percent in 1996 to 9.8 percent in 2016.

In other words, roughly 1 in 10, or 7.1 million, kids lives in a multigenerational household. At birth, about 15 percent of U.S. kids now live with a parent and grandparent – a rate that’s double that of countries like the U.K. and Australia.

Meanwhile, there was no real change in the percent of children living with aunts and uncles, other relatives or non-relatives. Nor did we find any evidence of an increase in “grandfamilies,” also known as “skipped-generation households.” These are homes in which a grandparent is raising a grandchild without the child’s parents living with them. Counter to some media reports, the share of children living in grandfamilies has held steady at roughly two percent since 1996.

And finally, there’s the fact that more people are receiving Social Security. Because Social Security gives grandparents a steady source of income, it could be that these grandparents are stepping in to help their grandchildren if their own children’s incomes are too low.

The findings are mixed because living arrangements are a complex topic. Motivation is difficult to distill. Sometimes people live together by choice – say, to be closer to family. Other times it’s by necessity – prompted by a crisis like a divorce, health problem or job loss.

From a policy perspective, who is in the household will likely impact the effectiveness of programs designed to help parents and kids. For example, programs that seek to improve the parenting skills of low-income moms generally focus only on moms. They’ll teach mothers to use positive parenting skills, like avoiding spanking their kids. But what if grandma still uses corporal punishment?

In other words, it’s a situation that most families would probably avoid if they could. So the fact that more people are living together suggests other larger societal and policy shifts are driving this trend.